To clarify the current situation of ketosis in dairy cattle on large-scale pastures in China and provide new insights,a questionnaire survey was conducted to analyze the incidence,preven-tion,treatment methods,and associated costs of ketosis in 79 large-scale pastures.The results showed that the average incidence of ketosis in dairy cows was 3.97％,with a cure rate of 92.40％.The order of importance of methods for preventing and controlling ketosis was as follows:feed for-mulation optimization＞blood ketone monitoring＞negative energy balance monitoring＞feed in-take monitoring＞milk yield monitoring.The most important treatment methods are intravenous glucose＞propylene glycol butyl phosphate＞vitamins＞choline.The most important diagnostic methods are blood ketone testing＞milk ketone testing＞negative energy balance testing＞clinical symptoms＞blood glucose testing.Economic analysis revealed that treatment costs were lower on larger farms and higher milk yields farms.Continuous optimization of feeding management,preven-tion,and control measures should be implemented on large-scale farms in China to reduce the oc-currence of ketosis in dairy cows.Additionally,more effective diagnostic and treatment methods should be employed to improve the cure rate and overall farm income.

To clarify the current situation of ketosis in dairy cattle on large-scale pastures in China and provide new insights,a questionnaire survey was conducted to analyze the incidence,preven-tion,treatment methods,and associated costs of ketosis in 79 large-scale pastures.The results showed that the average incidence of ketosis in dairy cows was 3.97％,with a cure rate of 92.40％.The order of importance of methods for preventing and controlling ketosis was as follows:feed for-mulation optimization＞blood ketone monitoring＞negative energy balance monitoring＞feed in-take monitoring＞milk yield monitoring.The most important treatment methods are intravenous glucose＞propylene glycol butyl phosphate＞vitamins＞choline.The most important diagnostic methods are blood ketone testing＞milk ketone testing＞negative energy balance testing＞clinical symptoms＞blood glucose testing.Economic analysis revealed that treatment costs were lower on larger farms and higher milk yields farms.Continuous optimization of feeding management,preven-tion,and control measures should be implemented on large-scale farms in China to reduce the oc-currence of ketosis in dairy cows.Additionally,more effective diagnostic and treatment methods should be employed to improve the cure rate and overall farm income.

OBJECTIVE:To establish a method for the simultaneous determination of narirutin,naringin,hesperiden and neo-hesperiden in Weisu granule. METHODS:UPLC was performed on the column of ACQUITY UPLC BEH C18 with mobile phase of acetonitrile-0.2% Phosphoric acid aqueous(gradient elution)at a flow rate of 0.40 ml/min,the detection wavelength was 284 nm, the column temperature was 30 ℃,and the injection volume was 1 μl. RESULTS:The linear range was 9.38-93.75 μg/ml for narirutin(r=0.999 7), 32.25-322.50 μg/ml for naringin(r=0.999 7), 11.25-112.50 μg/ml for hesperiden(r=0.999 9) and 11.88-118.75 μg/ml for neohesperidin(r=0.999 8);limits of quantitation were 20 ng,18 ng,18 ng and 18 ng,the limits of detec-tion were 6 ng,5 ng ,5 ng and 5 ng,respectively;RSDs of precision,stability and reproducibility tests were lower than 2.0%;re-coveries were 96.24%-103.12%(RSD=2.45%,n=6),98.43%-102.10%(RSD=1.42%,n=6),96.10%-101.41%(RSD=2.07%,n=6)and 95.57%-99.06%(RSD=1.44%,n=6),respectively. CONCLUSIONS:The method is rapid and efficient,and suitable for the simultaneous determination of narirutin,naringin,hesperiden and neohesperiden in Weisu granule.

Objective: To research the application of perspective imaging of intense laser proton beam in tumor cells, experi-ments are carried out on an ultra-intense picosecond pulsed laser facility, and the results of perspective imaging on biological samples by high energy proton beam, which is excitated among the interaction of picosecond laser with solid target, is showed. Methods: The laser energy is 12 J, the pulse width of laser is 1.5 ps, the laser focal spot diameter is 15 μm, the coefficientf or the off-axis paraboloid lens is 1.5. The target used in the experiment is made by coating a CH film with 1 μm on the back of the 15 pan-thick Cu. The distance between the proton source (laser spot) and the ant sample is 7 mm (i.e. the object distance), the distance between the sample and the RC film is 63 mm (i.e. the image distance). The detector is a stack of RCF or CR-39 films. Results: The ant is taken as the sample, a high energy proton beam, which is excitated as above on the rear surface of target, makes a 2-dimensional perspective imaging of an ant with high contrast, nanometer spatial resolution and density reso-lution. Conclusions: The result provided possibility of the application of perspective imaging of intense laser proton beam in tumor cells.